Determination of chlorpyrifos and its major breakdown products in technical formulations

Significance of impurities in the safety evaluation of crop protection products (IUPAC Technical Report)

“…The sulfotep content of the commercial products did not show any correlation with storage time. One 2-year-old sample containing 13.8 % TCP, 0.65 % sulfotep and trace amounts of chlorpyrifos oxon was reported as the cause of the death of 50 bulls treated directly with the product for ecto-parasite control [4]. Though the TCP was unlikely related to the toxicity of the product, the higher-than-normal levels detected were an indication of lengthy storage under adverse conditions.…”

“…A second phase of effort is to look for the probable impurities in technical products by applying a combination of various chromatographic and spectroscopic methods. Impurities of interest are usually analyzed by gas liquid chromatography (GLC), HPLC, and GC/MS (gas chromatography with mass spectrometric detection), alone or in combination with enrichment on chromatography columns [44,51] or initial separation on TLC plates [4]. Pavel and Kaiser [35] used TLC with enzyme inhibition or chemical detection to detect low concentrations of impurities in technical pesticides.…”

Separation and Determination of Process-related Impurities of Industrial Chlorpyriphos by Reversed-Phase High-Performance Liquid Chromatography

“…4 Many methods based on gas chromatography (GC), thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) have been reported for determination of organophosphorus pesticides in biological as well as environmental matrices. [5][6][7][8][9][10][11][12][13][14][15][16][17] Husain et al have developed gas and normal-phase liquid chromatographic methods for determination of chloropyridines in different process streams of CPP. 18 However, these methods do not address the problems of separation and quantitative determination of the hydrolysis product viz., HTCP, which is likely to be present in industrial products of CPP.…”

Determination of 3,5,6-trichloro-2-pyridinol (TCP) in water by a continuous competitive immunoassay system based on the streptavidin-biotin interaction

“…The current routine method, which is applied by the environmental regulatory agencies for measurement of other pesticides, is not suitable for the determination of TCP due to the physico-chemical properties of this compound. The determination of TCP has been carried out using GC with FID [12,13] or MS detection [14,15] which involves high cost and time consuming preparative steps such as extraction, cleanup, and derivatization. Recently, two methods based on immunoassay have been proposed as alternatives to the use of separation techniques.…”